1
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Sundelin T, Landry S, Axelsson J. Is snoozing losing? Why intermittent morning alarms are used and how they affect sleep, cognition, cortisol, and mood. J Sleep Res 2024; 33:e14054. [PMID: 37849039 DOI: 10.1111/jsr.14054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 09/09/2023] [Accepted: 09/12/2023] [Indexed: 10/19/2023]
Abstract
Pressing the snooze button is a common way to start the day, but little is known about this behaviour. Through two studies we determined predictors and effects of snoozing. In Study 1 (n = 1732) respondents described their waking habits, confirming that snoozing is widespread, especially in younger individuals and later chronotypes. Morning drowsiness and shorter sleep were also more common for those who snooze. Study 2 was a within-subjects laboratory study (with polysomnography) on habitual snoozers (n = 31), showing that 30 min of snoozing improved or did not affect performance on cognitive tests directly upon rising compared to an abrupt awakening. Bayes factors indicate varying strengths of this evidence. Snoozing resulted in about 6 min of lost sleep, while preventing awakenings from slow-wave sleep (N3). There were no clear effects of snoozing on the cortisol awakening response, morning sleepiness, mood, or overnight sleep architecture. A brief snooze period may thus help alleviate sleep inertia, without substantially disturbing sleep, for late chronotypes and those with morning drowsiness.
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Affiliation(s)
- Tina Sundelin
- Department of Psychology, Stockholm University, Stockholm, Sweden
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Shane Landry
- Department of Physiology, Biomedical Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - John Axelsson
- Department of Psychology, Stockholm University, Stockholm, Sweden
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
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2
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Hansson LS, Lasselin J, Tognetti A, Axelsson J, Olsson MJ, Sundelin T, Lekander M. The walking sick: Perception of experimental sickness from biological motion. Brain Behav Immun 2023; 113:319-327. [PMID: 37517742 DOI: 10.1016/j.bbi.2023.07.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 06/09/2023] [Accepted: 07/25/2023] [Indexed: 08/01/2023] Open
Abstract
Identification of sick conspecifics allows for avoidance of infectious threats, and is therefore an important behavioral defense against diseases. Here, we investigated if humans can identify sick individuals solely from biological motion and posture (using point-light displays). Additionally, we sought to determine which movements and sickness parameters would predict such detection. We collected video clips and derived point-light displays (one stride presented in a loop) of sick walkers (injected with lipopolysaccharide at 2.0 ng/kg body weight) and the same walkers when healthy (injected with saline). We then presented these displays to two groups, one group classified each walker as sick or healthy (study 1, n = 106), and the other group scored the walkers' health on a visual analogue scale (study 2, n = 106). The raters were able to identify sick individuals above chance, and rated sick walkers as having worse health, both from observing video clips and point-light displays. Furthermore, both sickness detection and worse apparent health were predicted by inflammation-induced increase in rigidity and slower walking, but not other cues. Altogether, these findings indicate that biological motion can serve as a sickness cue, possibly allowing humans to identify sick conspecifics from a distance, and thereby allowing for disease avoidance.
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Affiliation(s)
- L S Hansson
- Stress Research Institute, Department of Psychology, Stockholm University, Stockholm, Sweden; Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Osher Center for Integrative Health, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - J Lasselin
- Stress Research Institute, Department of Psychology, Stockholm University, Stockholm, Sweden; Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Osher Center for Integrative Health, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
| | - A Tognetti
- Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - J Axelsson
- Stress Research Institute, Department of Psychology, Stockholm University, Stockholm, Sweden; Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - M J Olsson
- Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - T Sundelin
- Stress Research Institute, Department of Psychology, Stockholm University, Stockholm, Sweden; Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - M Lekander
- Stress Research Institute, Department of Psychology, Stockholm University, Stockholm, Sweden; Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Osher Center for Integrative Health, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
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3
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Balter LJT, Sundelin T, Holding BC, Petrovic P, Axelsson J. Intelligence predicts better cognitive performance after normal sleep but larger vulnerability to sleep deprivation. J Sleep Res 2022:e13815. [PMID: 36579399 DOI: 10.1111/jsr.13815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 11/26/2022] [Accepted: 12/13/2022] [Indexed: 12/30/2022]
Abstract
Fluid intelligence is seen as a beneficial attribute, protecting against stress and ill-health. Whether intelligence provides resilience to the cognitive effects of insufficient sleep was tested in the current pre-registered experimental study. Participants (N = 182) completed the Raven's test (measuring fluid intelligence) and a normal night of sleep or a night of total sleep deprivation. Sleepiness and four cognitive tests were completed at 22:30 hours (baseline), and the following day after sleep manipulation. At baseline, higher fluid intelligence was associated with faster and more accurate arithmetic calculations, and better episodic memory, but not with spatial working memory, simple attention or sleepiness. Those with higher fluid intelligence were more, not less, impacted by sleep deprivation, evident for arithmetic ability, episodic memory and spatial working memory. We need to establish a more nuanced picture of the benefits of intelligence, where intelligence is not related to cognitive advantages in all situations.
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Affiliation(s)
- Leonie J T Balter
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Stress Research Institute and Department of Psychology, Stockholm University, Stockholm, Sweden
| | - Tina Sundelin
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Stress Research Institute and Department of Psychology, Stockholm University, Stockholm, Sweden
| | - Benjamin C Holding
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Sociology, Faculty of Social Science, University of Copenhagen, Copenhagen, Denmark
| | - Predrag Petrovic
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Center for Cognitive and Computational Neuropsychiatry, Karolinska Institutet, Stockholm, Sweden
| | - John Axelsson
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Stress Research Institute and Department of Psychology, Stockholm University, Stockholm, Sweden.,Center for Cognitive and Computational Neuropsychiatry, Karolinska Institutet, Stockholm, Sweden
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4
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Sundelin T, Holding BC. Trait Anxiety Does Not Predict the Anxiogenic Response to Sleep Deprivation. Front Behav Neurosci 2022; 16:880641. [PMID: 35910682 PMCID: PMC9332334 DOI: 10.3389/fnbeh.2022.880641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 06/16/2022] [Indexed: 11/21/2022] Open
Abstract
Sleep deprivation has in several studies been found to increase anxiety. However, the extent to which this anxiogenic effect depends on one’s underlying trait anxiety has not previously been determined. Using two separate sleep-loss experiments, the current research investigated whether trait anxiety (STAI-T) moderates the increase in state anxiety (STAI-S) following one night of total sleep loss (study 1, N = 182, age 25.3 ± 6.5, 103 women) and two nights of partial sleep restriction (study 2, N = 67, age 26.5 ± 7.4, 38 women). Both studies showed the expected anxiogenic effect of sleep loss, and a clear relationship between trait anxiety and state anxiety. However, the anxiogenic effect of sleep loss was not moderated by trait anxiety, as there was an equal impact regardless of trait anxiety level. These findings indicate that, although sleep loss is related to general anxiety as well as anxiety disorders, for a non-clinical sample the anxiogenic effect of short-term sleep loss is not affected by baseline levels of anxiety.
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Affiliation(s)
- Tina Sundelin
- Department of Psychology, Stockholm University, Stockholm, Sweden
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
- *Correspondence: Tina Sundelin,
| | - Benjamin C. Holding
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Department of Sociology, University of Copenhagen, Copenhagen, Denmark
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5
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Forte C, Voinea A, Chichirau M, Yeshmagambetova G, Albrecht LM, Erfurt C, Freundt LA, Carmo LOE, Henning RH, van der Horst ICC, Sundelin T, Wiering MA, Axelsson J, Epema AH. Deep Learning for Identification of Acute Illness and Facial Cues of Illness. Front Med (Lausanne) 2021; 8:661309. [PMID: 34381793 PMCID: PMC8350122 DOI: 10.3389/fmed.2021.661309] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 06/30/2021] [Indexed: 12/26/2022] Open
Abstract
Background: The inclusion of facial and bodily cues (clinical gestalt) in machine learning (ML) models improves the assessment of patients' health status, as shown in genetic syndromes and acute coronary syndrome. It is unknown if the inclusion of clinical gestalt improves ML-based classification of acutely ill patients. As in previous research in ML analysis of medical images, simulated or augmented data may be used to assess the usability of clinical gestalt. Objective: To assess whether a deep learning algorithm trained on a dataset of simulated and augmented facial photographs reflecting acutely ill patients can distinguish between healthy and LPS-infused, acutely ill individuals. Methods: Photographs from twenty-six volunteers whose facial features were manipulated to resemble a state of acute illness were used to extract features of illness and generate a synthetic dataset of acutely ill photographs, using a neural transfer convolutional neural network (NT-CNN) for data augmentation. Then, four distinct CNNs were trained on different parts of the facial photographs and concatenated into one final, stacked CNN which classified individuals as healthy or acutely ill. Finally, the stacked CNN was validated in an external dataset of volunteers injected with lipopolysaccharide (LPS). Results: In the external validation set, the four individual feature models distinguished acutely ill patients with sensitivities ranging from 10.5% (95% CI, 1.3-33.1% for the skin model) to 89.4% (66.9-98.7%, for the nose model). Specificity ranged from 42.1% (20.3-66.5%) for the nose model and 94.7% (73.9-99.9%) for skin. The stacked model combining all four facial features achieved an area under the receiver characteristic operating curve (AUROC) of 0.67 (0.62-0.71) and distinguished acutely ill patients with a sensitivity of 100% (82.35-100.00%) and specificity of 42.11% (20.25-66.50%). Conclusion: A deep learning algorithm trained on a synthetic, augmented dataset of facial photographs distinguished between healthy and simulated acutely ill individuals, demonstrating that synthetically generated data can be used to develop algorithms for health conditions in which large datasets are difficult to obtain. These results support the potential of facial feature analysis algorithms to support the diagnosis of acute illness.
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Affiliation(s)
- Castela Forte
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
- Department of Anesthesiology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
- Bernoulli Institute for Mathematics, Computer Science and Artificial Intelligence, University of Groningen, Groningen, Netherlands
| | - Andrei Voinea
- Bernoulli Institute for Mathematics, Computer Science and Artificial Intelligence, University of Groningen, Groningen, Netherlands
| | - Malina Chichirau
- Bernoulli Institute for Mathematics, Computer Science and Artificial Intelligence, University of Groningen, Groningen, Netherlands
| | - Galiya Yeshmagambetova
- Bernoulli Institute for Mathematics, Computer Science and Artificial Intelligence, University of Groningen, Groningen, Netherlands
| | - Lea M. Albrecht
- Department of Anesthesiology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Chiara Erfurt
- Department of Anesthesiology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Liliane A. Freundt
- Department of Anesthesiology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Luisa Oliveira e Carmo
- Department of Anesthesiology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Robert H. Henning
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Iwan C. C. van der Horst
- Department of Intensive Care Medicine, Maastricht University Medical Centre+, University Maastricht, Maastricht, Netherlands
| | - Tina Sundelin
- Department of Psychology, Stress Research Institute, Stockholm University, Stockholm, Sweden
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Marco A. Wiering
- Bernoulli Institute for Mathematics, Computer Science and Artificial Intelligence, University of Groningen, Groningen, Netherlands
| | - John Axelsson
- Department of Psychology, Stress Research Institute, Stockholm University, Stockholm, Sweden
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Anne H. Epema
- Department of Anesthesiology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
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6
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Arshamian A, Sundelin T, Wnuk E, O'Meara C, Burenhult N, Rodriguez GG, Lekander M, Olsson MJ, Lasselin J, Axelsson J, Majid A. Human sickness detection is not dependent on cultural experience. Proc Biol Sci 2021; 288:20210922. [PMID: 34255999 PMCID: PMC8277478 DOI: 10.1098/rspb.2021.0922] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Animals across phyla can detect early cues of infection in conspecifics, thereby reducing the risk of contamination. It is unknown, however, if humans can detect cues of sickness in people belonging to communities with whom they have limited or no experience. To test this, we presented Western faces photographed 2 h after the experimental induction of an acute immune response to one Western and five non-Western communities, including small-scale hunter-gatherer and large urban-dwelling communities. All communities could detect sick individuals. There were group differences in performance but Western participants, who observed faces from their own community, were not systematically better than all non-Western participants. At odds with the common belief that sickness detection of an out-group member should be biased to err on the side of caution, the majority of non-Western communities were unbiased. Our results show that subtle cues of a general immune response are recognized across cultures and may aid in detecting infectious threats.
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Affiliation(s)
- Artin Arshamian
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Tina Sundelin
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Stress Research Institute, Stockholm University, Stockholm, Sweden
| | - Ewelina Wnuk
- Department of Anthropology, University College London, London, UK
| | - Carolyn O'Meara
- Instituto de Investigaciones Filológicas, National Autonomous University of Mexico in Mexico City, Mexico
| | - Niclas Burenhult
- Centre for Languages and Literature, Lund University, Sweden.,Lund University Humanities Laboratory, Lund University, Sweden
| | | | - Mats Lekander
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Stress Research Institute, Stockholm University, Stockholm, Sweden
| | - Mats J Olsson
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Julie Lasselin
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Stress Research Institute, Stockholm University, Stockholm, Sweden
| | - John Axelsson
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Stress Research Institute, Stockholm University, Stockholm, Sweden
| | - Asifa Majid
- Department of Psychology, University of York, York, UK
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7
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Axelsson J, Ingre M, Kecklund G, Lekander M, Wright KP, Sundelin T. Sleepiness as motivation: a potential mechanism for how sleep deprivation affects behavior. Sleep 2021; 43:5648004. [PMID: 31782961 PMCID: PMC7294403 DOI: 10.1093/sleep/zsz291] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 10/16/2019] [Indexed: 01/07/2023] Open
Abstract
STUDY OBJECTIVES To determine how sleepiness and sleep deprivation drive the motivation to engage in different behaviors. METHODS We studied the sleepiness of 123 participants who had been randomized to sleep deprivation or normal sleep, and their willingness to engage in a range of everyday behaviors. RESULTS Self-reported sleepiness was a strong predictor of the motivation to engage in sleep-preparatory behaviors such as shutting one's eyes (OR = 2.78, 95% CI: 2.19-3.52 for each step up on the Karolinska Sleepiness Scale) and resting (OR = 3.20, CI: 2.46-4.16). Sleepiness was also related to the desire to be cared for by a loved one (OR = 1.49, CI: 1.22-1.82), and preparedness to utilize monetary and energy resources to get to sleep. Conversely, increased sleepiness was associated with a decreased motivation for social and physical activities (e.g. be with friends OR = 0.71, CI: 0.61-0.82; exercise OR = 0.65, CI: 0.56-0.76). Sleep deprivation had similar effects as sleepiness on these behaviors. Neither sleepiness nor sleep deprivation had strong associations with hunger, thirst, or food preferences. CONCLUSIONS Our findings indicate that sleepiness is a dynamic motivational drive that promotes sleep-preparatory behaviors and competes with other drives and desired outcomes. Consequently, sleepiness may be a central mechanism by which impaired alertness, for example, due to insufficient sleep, contributes to poor quality of life and adverse health. We propose that sleepiness helps organize behaviors toward the specific goal of assuring sufficient sleep, in competition with other needs and incentives. A theoretical framework on sleepiness and its behavioral consequences are likely to improve our understanding of several disease mechanisms.
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Affiliation(s)
- John Axelsson
- Stress Research Institute, Stockholm University, Stockholm, Sweden.,Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Michael Ingre
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Institute for Globally Distributed Research and Education (IGDORE), Stockholm, Sweden
| | - Göran Kecklund
- Stress Research Institute, Stockholm University, Stockholm, Sweden.,Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Mats Lekander
- Stress Research Institute, Stockholm University, Stockholm, Sweden.,Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Kenneth P Wright
- Department of Integrative Physiology, University of Colorado Boulder, CO
| | - Tina Sundelin
- Stress Research Institute, Stockholm University, Stockholm, Sweden.,Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Psychology, New York University, NY
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8
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Holding BC, Ingre M, Petrovic P, Sundelin T, Axelsson J. Quantifying Cognitive Impairment After Sleep Deprivation at Different Times of Day: A Proof of Concept Using Ultra-Short Smartphone-Based Tests. Front Behav Neurosci 2021; 15:666146. [PMID: 33927603 PMCID: PMC8076531 DOI: 10.3389/fnbeh.2021.666146] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 03/19/2021] [Indexed: 11/28/2022] Open
Abstract
Cognitive functioning is known to be impaired following sleep deprivation and to fluctuate depending on the time of day. However, most methods of assessing cognitive performance remain impractical for environments outside of the lab. This study investigated whether 2-min smartphone-based versions of commonly used cognitive tests could be used to assess the effects of sleep deprivation and time of day on diverse cognitive functions. After three nights of normal sleep, participants (N = 182) were randomised to either one night of sleep deprivation or a fourth night of normal sleep. Using the Karolinska WakeApp (KWA), participants completed a battery of 2-min cognitive tests, including measures of attention, arithmetic ability, episodic memory, working memory, and a Stroop test for cognitive conflict and behavioural adjustment. A baseline measurement was completed at 22:30 h, followed by three measurements the following day at approximately 08:00 h, 12:30 h, and 16:30 h. Sleep deprivation led to performance impairments in attention, arithmetic ability, episodic memory, and working memory. No effect of sleep deprivation was observed in the Stroop test. There were variations in attention and arithmetic test performance across different times of day. The effect of sleep deprivation on all cognitive tests was also found to vary at different times of day. In conclusion, this study shows that the KWA's 2-min cognitive tests can be used to detect cognitive impairments following sleep deprivation, and fluctuations in cognitive performance relating to time of day. The results demonstrate the potential of using brief smartphone-based tasks to measure a variety of cognitive abilities within sleep and fatigue research.
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Affiliation(s)
- Benjamin C. Holding
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Department of Sociology, University of Copenhagen, Copenhagen, Denmark
| | - Michael Ingre
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Department of Psychology, Stockholm University, Stockholm, Sweden
| | - Predrag Petrovic
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Tina Sundelin
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Department of Psychology, Stockholm University, Stockholm, Sweden
| | - John Axelsson
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Department of Psychology, Stockholm University, Stockholm, Sweden
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9
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Balter LJT, Sundelin T, Axelsson J. Sickness and sleep health predict frustration and affective responses to a frustrating trigger. Sci Rep 2021; 11:1542. [PMID: 33452313 PMCID: PMC7810868 DOI: 10.1038/s41598-020-80461-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 12/21/2020] [Indexed: 11/09/2022] Open
Abstract
Fluctuations in health and sleep are common, but we know surprisingly little about how these daily life stressors affect one's level of frustration and sensitivity to becoming frustrated. In this pre-registered study, 517 participants (Mage = 30.4, SD = 10.4) reported their current sickness symptoms, health status, sleepiness, and sleep duration and quality the previous night. They also rated their general frustration and mood before and after a mild frustration-eliciting task. In the task, participants were instructed to copy geometric shapes onto a piece of paper, without lifting the pen from the paper. Participants were given three minutes to copy the eight shapes, but in order to induce frustration half of them were unsolvable. The study was subsequently repeated in an independent sample (N = 113). Frustration increased in response to the task; however, those with the worst sickness symptoms or sleep health reduced or did not change their frustration levels. Instead, across both studies, frustration was already high at baseline for these individuals. These findings indicate that being sick or having poor sleep is related to high general frustration, but resilience to further frustration due to mild frustrating situations.
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Affiliation(s)
| | - Tina Sundelin
- Stress Research Institute, Stockholm University, Stockholm, Sweden.,Department of Clinical Neuroscience, Karolinska Institutet, Solna, Sweden
| | - John Axelsson
- Stress Research Institute, Stockholm University, Stockholm, Sweden.,Department of Clinical Neuroscience, Karolinska Institutet, Solna, Sweden
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10
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Härdelin G, Holding BC, Reess T, Geranmayeh A, Axelsson J, Sundelin T. Do Mothers Have Worse Sleep Than Fathers? Sleep Imbalance, Parental Stress, and Relationship Satisfaction in Working Parents. Nat Sci Sleep 2021; 13:1955-1966. [PMID: 34764711 PMCID: PMC8576759 DOI: 10.2147/nss.s323991] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 09/07/2021] [Indexed: 12/16/2022] Open
Abstract
PURPOSE Previous research indicates that mothers take a larger responsibility for child care during the night and that they have more disturbed sleep than fathers. The purpose of this study was to determine whether such a sleep imbalance exists in working parents of young children, and the extent to which it depends on the way sleep is measured. The study also examined whether imbalanced sleep between parents predicts parental stress and relationship satisfaction. METHODS Sleep was measured for seven consecutive days in 60 parenting couples (average age of the youngest child: 3.3 years ± SD 2.5 years). Actigraphs were worn across the week, and ratings of sleep, parental stress, and relationship satisfaction were made daily. RESULTS Mothers perceived their sleep quality as worse (b= -0.38 scale units, p<0.001), with more wake periods (b= +0.96 awakenings, p<0.001) but with longer sleep duration (b= +32.4 min, p<0.01) than fathers. Actigraphy data confirmed that mothers slept longer than fathers (b= +28.03 min, p<0.001), but no significant differences were found for wake time, number of awakenings or who woke up first during shared awakenings. Furthermore, there was no difference in whether mothers and fathers slept sufficiently. The level of sleep imbalance between parents did not predict parental stress. A larger imbalance in subjective sleep sufficiency predicted decreased relationship satisfaction for fathers (b= -0.13 scale units, p<0.01) but increased relationship satisfaction for mothers (b= 0.14 scale units, p<0.05). No other sleep imbalance measures predicted relationship satisfaction. CONCLUSION Our findings are in line with previous research on sleep in men and women in general, with longer sleep and subjective reports of sleep disturbances in women, rather than previous research on sleep in parents of young children. Thus, we found no evidence of a sleep imbalance when both parents have similar working responsibilities.
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Affiliation(s)
- Göran Härdelin
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Psychology, Stockholm University, Stockholm, Sweden
| | - Benjamin C Holding
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Sociology, University of Copenhagen, Copenhagen, Denmark
| | - Tim Reess
- Department of Psychology, Stockholm University, Stockholm, Sweden
| | - Anahita Geranmayeh
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Psychology, Stockholm University, Stockholm, Sweden
| | - John Axelsson
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Psychology, Stockholm University, Stockholm, Sweden
| | - Tina Sundelin
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Psychology, Stockholm University, Stockholm, Sweden
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11
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Floros O, Axelsson J, Almeida R, Tigerström L, Lekander M, Sundelin T, Petrovic P. Vulnerability in Executive Functions to Sleep Deprivation Is Predicted by Subclinical Attention-Deficit/Hyperactivity Disorder Symptoms. Biol Psychiatry Cogn Neurosci Neuroimaging 2020; 6:290-298. [PMID: 33341402 DOI: 10.1016/j.bpsc.2020.09.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 09/30/2020] [Accepted: 09/30/2020] [Indexed: 12/27/2022]
Abstract
BACKGROUND Sleep loss results in state instability of cognitive functioning. It is not known whether this effect is more expressed when there is an increased cognitive demand. Moreover, while vulnerability to sleep loss varies substantially among individuals, it is not known why some people are more affected than others. We hypothesized that top-down regulation was specifically affected by sleep loss and that subclinical inattention and emotional instability traits, related to attention-deficit/hyperactivity disorder symptoms, predict this vulnerability in executive function and emotion regulation, respectively. METHODS Healthy subjects (ages 17-45 years) rated trait inattention and emotional instability before being randomized to either a night of normal sleep (n = 86) or total sleep deprivation (n = 87). Thereafter, they performed a neutral and emotional computerized Stroop task, involving words and faces. Performance was characterized primarily by cognitive conflict reaction time and reaction time variability (RTV), mirroring conflict cost in top-down regulation. RESULTS Sleep loss led to increased cognitive conflict RTV. Moreover, a higher level of inattention predicted increased cognitive conflict RTV in the neutral Stroop task after sleep deprivation (r = .30, p = .0055) but not after normal sleep (r = .055, p = .65; interaction effect β = 6.19, p = .065). This association remained after controlling for cognitive conflict reaction time and emotional instability, suggesting domain specificity. Correspondingly, emotional instability predicted cognitive conflict RTV for the emotional Stroop task only after sleep deprivation, although this effect was nonsignificant after correcting for multiple comparisons. CONCLUSIONS Our findings suggest that sleep deprivation affects cognitive conflict variability and that less stable performance in executive functioning may surface after sleep loss in vulnerable individuals characterized by subclinical symptoms of inattention.
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Affiliation(s)
- Orestis Floros
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - John Axelsson
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Stress Research Institute, Stockholm, Sweden; Department of Psychology, Stockholm University, Stockholm, Sweden
| | - Rita Almeida
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Stockholm University Brain Imaging Center, Stockholm, Sweden
| | - Lars Tigerström
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Mats Lekander
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Stress Research Institute, Stockholm, Sweden; Department of Psychology, Stockholm University, Stockholm, Sweden
| | - Tina Sundelin
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Stress Research Institute, Stockholm, Sweden; Department of Psychology, Stockholm University, Stockholm, Sweden
| | - Predrag Petrovic
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
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12
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Sarolidou G, Axelsson J, Kimball BA, Sundelin T, Regenbogen C, Lundström JN, Lekander M, Olsson MJ. People expressing olfactory and visual cues of disease are less liked. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190272. [PMID: 32306878 DOI: 10.1098/rstb.2019.0272] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
For humans, like other social animals, behaviour acts as a first line of defence against pathogens. A key component is the ability to detect subtle perceptual cues of sick conspecifics. The present study assessed the effects of endotoxin-induced olfactory and visual sickness cues on liking, as well as potential involved mechanisms. Seventy-seven participants were exposed to sick and healthy facial pictures and body odours from the same individual in a 2 × 2 factorial design while disgust-related facial electromyography (EMG) was recorded. Following exposure, participants rated their liking of the person presented. In another session, participants also answered questionnaires on perceived vulnerability to disease, disgust sensitivity and health anxiety. Lower ratings of liking were linked to both facial and body odour disease cues as main effects. Disgust, as measured by EMG, did not seem to be the mediating mechanism, but participants who perceived themselves as more prone to disgust, and as more vulnerable to disease, liked presented persons less irrespectively of their health status. Concluding, olfactory and visual sickness cues that appear already a few hours after the experimental induction of systemic inflammation have implications for human sociality and may as such be a part of a behavioural defence against disease. This article is part of the Theo Murphy meeting issue 'Olfactory communication in humans'.
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Affiliation(s)
- Georgia Sarolidou
- Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Sweden
| | - John Axelsson
- Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Sweden.,Stress Research Institute, Stockholm University, Stockholm, Sweden.,Osher Center for Integrative Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Bruce A Kimball
- USDA-APHIS-WS, National Wildlife Research Center, Monell Chemical Senses Center, Philadelphia, PA, USA
| | - Tina Sundelin
- Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Sweden.,Stress Research Institute, Stockholm University, Stockholm, Sweden
| | - Christina Regenbogen
- Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Sweden.,Institute of Neuroscience and Medicine: JARA-Institute Brain Structure Function Relationship (INM-3), Research Center Jülich, Jülich, Germany.,Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, Aachen, Germany
| | - Johan N Lundström
- Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Sweden.,Department of Psychology, University of Pennsylvania, Philadelphia, USA.,Stockholm University Brain Imaging Centre, Stockholm, Sweden.,Monell Chemical Senses Center, Philadelphia, PA, USA
| | - Mats Lekander
- Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Sweden.,Stress Research Institute, Stockholm University, Stockholm, Sweden.,Osher Center for Integrative Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Mats J Olsson
- Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Sweden
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13
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Lasselin J, Sundelin T, Wayne PM, Olsson MJ, Paues Göranson S, Axelsson J, Lekander M. Biological motion during inflammation in humans. Brain Behav Immun 2020; 84:147-153. [PMID: 31785395 PMCID: PMC7010549 DOI: 10.1016/j.bbi.2019.11.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 11/19/2019] [Accepted: 11/23/2019] [Indexed: 12/26/2022] Open
Abstract
Biological motion is a powerful perceptual cue that can reveal important information about the inner state of an individual. Activation of inflammatory processes likely leads to changes in gait, posture, and mobility patterns, but the specific characteristics of inflammation-related biological motion have not been characterized. The aim of this study was to determine the effect of inflammation on gait and motion in humans. Systemic inflammation was induced in 19 healthy volunteers with an intravenous injection of lipopolysaccharide (2 ng/kg body weight). Biological motion parameters (walking speed, stride length and time, arm, leg, head, and shoulder angles) were assessed during a walking paradigm and the timed-up-and-go test. Cytokine concentrations, body temperature, and sickness symptoms were measured. During inflammation, compared to placebo, participants exhibited shorter, slower, and wider strides, less arm extension, less knee flexion, and a more downward-tilting head while walking. They were also slower and took a shorter first step in the timed-up-and-go test. Higher interleukin-6 concentrations, stronger sickness symptoms, and lower body temperature predicted the inflammation-related alterations in biological motion. These findings show that biological motion contains clear information about the inflammatory status of an individual, and may be used by peers or artificial intelligence to recognize that someone is sick or contagious.
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Affiliation(s)
- J Lasselin
- Stress Research Institute, Stockholm University, 10691 Stockholm, Sweden; Department of Clinical Neuroscience, Division for Psychology, Karolinska Institutet, Nobels väg 9, 17177 Stockholm, Sweden; Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, Hufelandstrasse 55, 45122 Essen, Germany.
| | - T Sundelin
- Stress Research Institute, Stockholm University, 10691 Stockholm, Sweden; Department of Clinical Neuroscience, Division for Psychology, Karolinska Institutet, Nobels väg 9, 17177 Stockholm, Sweden; Department of Psychology, New York University, 6 Washington Place, 10003 New York, NY, USA
| | - P M Wayne
- Osher Center for Integrative Medicine, Division of Preventive Medicine, Brigham and Women's Hospital and Harvard Medical School, 75 Francis Stress, 02115 Boston, MA, USA
| | - M J Olsson
- Department of Clinical Neuroscience, Division for Psychology, Karolinska Institutet, Nobels väg 9, 17177 Stockholm, Sweden
| | - S Paues Göranson
- Department of Clinical Sciences, Danderyd Hospital, Karolinska Institutet, 18288 Stockholm, Sweden
| | - J Axelsson
- Stress Research Institute, Stockholm University, 10691 Stockholm, Sweden; Department of Clinical Neuroscience, Division for Psychology, Karolinska Institutet, Nobels väg 9, 17177 Stockholm, Sweden; Osher Center for Integrative Medicine, Karolinska Institutet, Nobels väg 9, 17177 Stockholm, Sweden
| | - M Lekander
- Stress Research Institute, Stockholm University, 10691 Stockholm, Sweden; Department of Clinical Neuroscience, Division for Psychology, Karolinska Institutet, Nobels väg 9, 17177 Stockholm, Sweden; Osher Center for Integrative Medicine, Karolinska Institutet, Nobels väg 9, 17177 Stockholm, Sweden
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14
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Holding BC, Sundelin T, Cairns P, Perrett DI, Axelsson J. The effect of sleep deprivation on objective and subjective measures of facial appearance. J Sleep Res 2019; 28:e12860. [PMID: 31006920 DOI: 10.1111/jsr.12860] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 03/11/2019] [Accepted: 03/12/2019] [Indexed: 11/28/2022]
Abstract
The faces of people who are sleep deprived are perceived by others as looking paler, less healthy and less attractive compared to when well rested. However, there is little research using objective measures to investigate sleep-loss-related changes in facial appearance. We aimed to assess the effects of sleep deprivation on skin colour, eye openness, mouth curvature and periorbital darkness using objective measures, as well as to replicate previous findings for subjective ratings. We also investigated the extent to which these facial features predicted ratings of fatigue by others and could be used to classify the sleep condition of the person. Subjects (n = 181) were randomised to one night of total sleep deprivation or a night of normal sleep (8-9 hr in bed). The following day facial photographs were taken and, in a subset (n = 141), skin colour was measured using spectrophotometry. A separate set of participants (n = 63) later rated the photographs in terms of health, paleness and fatigue. The photographs were also digitally analysed with respect to eye openness, mouth curvature and periorbital darkness. The results showed that neither sleep deprivation nor the subjects' sleepiness was related to differences in any facial variable. Similarly, there was no difference in subjective ratings between the groups. Decreased skin yellowness, less eye openness, downward mouth curvature and periorbital darkness all predicted increased fatigue ratings by others. However, the combination of appearance variables could not be accurately used to classify sleep condition. These findings have implications for both face-to-face and computerised visual assessment of sleep loss and fatigue.
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Affiliation(s)
- Benjamin C Holding
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Tina Sundelin
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Psychology, New York University, New York, NY.,Stress Research Institute, Stockholm University, Stockholm, Sweden
| | - Patrick Cairns
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, UK
| | - David I Perrett
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, UK
| | - John Axelsson
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Stress Research Institute, Stockholm University, Stockholm, Sweden
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15
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Holding BC, Sundelin T, Lekander M, Axelsson J. Sleep deprivation and its effects on communication during individual and collaborative tasks. Sci Rep 2019; 9:3131. [PMID: 30816244 PMCID: PMC6395705 DOI: 10.1038/s41598-019-39271-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 01/21/2019] [Indexed: 11/30/2022] Open
Abstract
Sleep loss has been shown to cause impairments in a number of aspects central for successful communication, ranging from poorer linguistic comprehension to alterations in speech prosody. However, the effect of sleep loss on actual communication is unknown. This study investigated how a night of sleep deprivation affected performance during multiple tasks designed to test verbal communication. Healthy participants (N = 183) spent 8–9 hours per night in bed for three nights and were then randomised to either one night of total sleep deprivation or a fourth night with 8–9 hours in bed. The following day, participants completed two tasks together with another participant: a model-building task and a word-description task. Differences in performance of these tasks were assessed alongside speaking duration, speaking volume, and speaking volume consistency. Additionally, participants individually completed a verbal fluency assessment. Performance on the model-building task was worse if the model-builder was sleep deprived, whereas sleep deprivation in the instruction-giver predicted an improvement. Word-description, verbal fluency, speech duration, speaking volume, and speaking volume consistency were not affected. The results suggest that sleep deprivation leads to changes in communicative performance during instructive tasks, while simpler word-description tasks appear resilient.
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Affiliation(s)
- Benjamin C Holding
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
| | - Tina Sundelin
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Psychology, New York University, New York, USA
| | - Mats Lekander
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Stress Research Institute, Stockholm University, Stockholm, Sweden
| | - John Axelsson
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Stress Research Institute, Stockholm University, Stockholm, Sweden
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16
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Axelsson J, Sundelin T, Olsson MJ, Sorjonen K, Axelsson C, Lasselin J, Lekander M. Identification of acutely sick people and facial cues of sickness. Proc Biol Sci 2019; 285:rspb.2017.2430. [PMID: 29298938 DOI: 10.1098/rspb.2017.2430] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 11/29/2017] [Indexed: 12/23/2022] Open
Abstract
Detection and avoidance of sick individuals have been proposed as essential components in a behavioural defence against disease, limiting the risk of contamination. However, almost no knowledge exists on whether humans can detect sick individuals, and if so by what cues. Here, we demonstrate that untrained people can identify sick individuals above chance level by looking at facial photos taken 2 h after injection with a bacterial stimulus inducing an immune response (2.0 ng kg-1 lipopolysaccharide) or placebo, the global sensitivity index being d' = 0.405. Signal detection analysis (receiver operating characteristic curve area) showed an area of 0.62 (95% confidence intervals 0.60-0.63). Acutely sick people were rated by naive observers as having paler lips and skin, a more swollen face, droopier corners of the mouth, more hanging eyelids, redder eyes, and less glossy and patchy skin, as well as appearing more tired. Our findings suggest that facial cues associated with the skin, mouth and eyes can aid in the detection of acutely sick and potentially contagious people.
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Affiliation(s)
- John Axelsson
- Stress Research Institute, Stockholm University, Stockholm, Sweden .,Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Tina Sundelin
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Psychology, New York University, New York, NY, USA
| | - Mats J Olsson
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Kimmo Sorjonen
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Charlotte Axelsson
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Julie Lasselin
- Stress Research Institute, Stockholm University, Stockholm, Sweden.,Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Institute of Medical Psychology and Behavioral Immunobiology, Universitätsklinikum Essen, Essen, Germany
| | - Mats Lekander
- Stress Research Institute, Stockholm University, Stockholm, Sweden.,Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
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17
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Axelsson J, Sundelin T, Lasselin J, Lekander M. How can we improve identification of contagious individuals? Factors influencing sickness detection. Proc Biol Sci 2018; 285:rspb.2018.2005. [PMID: 30355716 DOI: 10.1098/rspb.2018.2005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 10/03/2018] [Indexed: 01/18/2023] Open
Affiliation(s)
- John Axelsson
- Stress Research Institute, Stockholm University, Stockholm, Sweden .,Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Tina Sundelin
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Psychology, New York University, New York, NY, USA
| | - Julie Lasselin
- Stress Research Institute, Stockholm University, Stockholm, Sweden.,Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Institute of Medical Psychology and Behavioral Immunobiology, Universitätsklinikum Essen, Essen, Germany
| | - Mats Lekander
- Stress Research Institute, Stockholm University, Stockholm, Sweden.,Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
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18
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Holding BC, Laukka P, Fischer H, Bänziger T, Axelsson J, Sundelin T. Multimodal Emotion Recognition Is Resilient to Insufficient Sleep: Results From Cross-Sectional and Experimental Studies. Sleep 2018; 40:4096875. [PMID: 28958084 DOI: 10.1093/sleep/zsx145] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Objectives Insufficient sleep has been associated with impaired recognition of facial emotions. However, previous studies have found inconsistent results, potentially stemming from the type of static picture task used. We therefore examined whether insufficient sleep was associated with decreased emotion recognition ability in two separate studies using a dynamic multimodal task. Methods Study 1 used a cross-sectional design consisting of 291 participants with questionnaire measures assessing sleep duration and self-reported sleep quality for the previous night. Study 2 used an experimental design involving 181 participants where individuals were quasi-randomized into either a sleep-deprivation (N = 90) or a sleep-control (N = 91) condition. All participants from both studies were tested on the same forced-choice multimodal test of emotion recognition to assess the accuracy of emotion categorization. Results Sleep duration, self-reported sleep quality (study 1), and sleep deprivation (study 2) did not predict overall emotion recognition accuracy or speed. Similarly, the responses to each of the twelve emotions tested showed no evidence of impaired recognition ability, apart from one positive association suggesting that greater self-reported sleep quality could predict more accurate recognition of disgust (study 1). Conclusions The studies presented here involve considerably larger samples than previous studies and the results support the null hypotheses. Therefore, we suggest that the ability to accurately categorize the emotions of others is not associated with short-term sleep duration or sleep quality and is resilient to acute periods of insufficient sleep.
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Affiliation(s)
| | - Petri Laukka
- Department of Psychology, Stockholm University, Sweden
| | - Håkan Fischer
- Department of Psychology, Stockholm University, Sweden
| | | | - John Axelsson
- Department of Clinical Neuroscience, Karolinska Institutet, Sweden.,Stress Research Institute, Stockholm University, Sweden
| | - Tina Sundelin
- Department of Clinical Neuroscience, Karolinska Institutet, Sweden.,Stress Research Institute, Stockholm University, Sweden
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19
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Holding B, Sundelin T, Axelsson J. Changes in skin color after sleep deprivation: objective, subjective or null? Sleep Med 2017. [DOI: 10.1016/j.sleep.2017.11.385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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20
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Sundelin T, Lekander M, Sorjonen K, Axelsson J. Negative effects of restricted sleep on facial appearance and social appeal. R Soc Open Sci 2017; 4:160918. [PMID: 28572989 PMCID: PMC5451790 DOI: 10.1098/rsos.160918] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 04/13/2017] [Indexed: 06/07/2023]
Abstract
The importance of assessing evolutionarily relevant social cues suggests that humans should be sensitive to others' sleep history, as this may indicate something about their health as well as their capacity for social interaction. Recent findings show that acute sleep deprivation and looking tired are related to decreased attractiveness and health, as perceived by others. This suggests that one might also avoid contact with sleep-deprived, or sleepy-looking, individuals, as a strategy to reduce health risk and poor interactions. In this study, 25 participants (14 females, age range 18-47 years) were photographed after 2 days of sleep restriction and after normal sleep, in a balanced design. The photographs were rated by 122 raters (65 females, age range 18-65 years) on how much they would like to socialize with the participants. They also rated participants' attractiveness, health, sleepiness and trustworthiness. The results show that raters were less inclined to socialize with individuals who had gotten insufficient sleep. Furthermore, when sleep-restricted, participants were perceived as less attractive, less healthy and more sleepy. There was no difference in perceived trustworthiness. These findings suggest that naturalistic sleep loss can be detected in a face and that people are less inclined to interact with a sleep-deprived individual.
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Affiliation(s)
- Tina Sundelin
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm 17177, Sweden
- Department of Psychology, Stockholm University, Stockholm 10691, Sweden
| | - Mats Lekander
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm 17177, Sweden
- Stress Research Institute, Stockholm University, Stockholm 10691, Sweden
| | - Kimmo Sorjonen
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm 17177, Sweden
| | - John Axelsson
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm 17177, Sweden
- Stress Research Institute, Stockholm University, Stockholm 10691, Sweden
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21
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Karshikoff B, Sundelin T, Lasselin J. Role of Inflammation in Human Fatigue: Relevance of Multidimensional Assessments and Potential Neuronal Mechanisms. Front Immunol 2017; 8:21. [PMID: 28163706 PMCID: PMC5247454 DOI: 10.3389/fimmu.2017.00021] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Accepted: 01/05/2017] [Indexed: 12/21/2022] Open
Abstract
Fatigue is a highly disabling symptom in various medical conditions. While inflammation has been suggested as a potential contributor to the development of fatigue, underlying mechanisms remain poorly understood. In this review, we propose that a better assessment of central fatigue, taking into account its multidimensional features, could help elucidate the role and mechanisms of inflammation in fatigue development. A description of the features of central fatigue is provided, and the current evidence describing the association between inflammation and fatigue in various medical conditions is reviewed. Additionally, the effect of inflammation on specific neuronal processes that may be involved in distinct fatigue dimensions is described. We suggest that the multidimensional aspects of fatigue should be assessed in future studies of inflammation-induced fatigue and that this would benefit the development of effective therapeutic interventions.
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Affiliation(s)
- Bianka Karshikoff
- Division for Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Solna, Sweden; Stress Research Institute, Stockholm University, Stockholm, Sweden
| | - Tina Sundelin
- Division for Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Solna, Sweden; Department of Psychology, Stockholm University, Stockholm, Sweden
| | - Julie Lasselin
- Division for Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Solna, Sweden; Stress Research Institute, Stockholm University, Stockholm, Sweden; Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, Essen, Germany
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22
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Talamas SN, Mavor KI, Axelsson J, Sundelin T, Perrett DI. Eyelid-openness and mouth curvature influence perceived intelligence beyond attractiveness. J Exp Psychol Gen 2016; 145:603-620. [PMID: 26913618 DOI: 10.1037/xge0000152] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Impression formation is profoundly influenced by facial attractiveness, but the existence of facial cues which affect judgments beyond such an "attractiveness halo" may be underestimated. Because depression and tiredness adversely affect cognitive capacity, we reasoned that facial cues to mood (mouth curvature) and alertness (eyelid-openness) affect impressions of intellectual capacity. Over 4 studies we investigated the influence of these malleable facial cues on first impressions of intelligence. In Studies 1 and 2 we scrutinize the perceived intelligence and attractiveness ratings of images of 100 adults (aged 18-33) and 90 school-age children (aged 5-17), respectively. Intelligence impression was partially mediated by attractiveness, but independent effects of eyelid-openness and subtle smiling were found that enhanced intelligence ratings independent of attractiveness. In Study 3 we digitally manipulated stimuli to have altered eyelid-openness or mouth curvature and found that each independent manipulation had an influence on perceptions of intelligence. In a final set of stimuli (Study 4) we explored changes in these cues before and after sleep restriction, to examine whether natural variations in these cues according to sleep condition can influence perceptions. In Studies 3 and 4 variations with increased eyelid-openness and mouth curvature were found to relate positively to intelligence ratings. These findings suggest potential overgeneralizations based on subtle facial cues that indicate mood and tiredness, both of which alter cognitive ability. These findings also have important implications for students who are directly influenced by expectations of ability and teachers who may form expectations based on initial perceptions of intelligence.
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Affiliation(s)
- Sean N Talamas
- School of Psychology and Neuroscience, University of St. Andrews
| | - Kenneth I Mavor
- School of Psychology and Neuroscience, University of St. Andrews
| | - John Axelsson
- Department of Clinical Neuroscience, Division for Psychology, Karolinska Institute
| | | | - David I Perrett
- School of Psychology and Neuroscience, University of St. Andrews
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23
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Sundelin T, Karshikoff B, Axelsson E, Höglund CO, Lekander M, Axelsson J. Sick man walking: Perception of health status from body motion. Brain Behav Immun 2015; 48:53-6. [PMID: 25801061 DOI: 10.1016/j.bbi.2015.03.007] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Revised: 03/04/2015] [Accepted: 03/14/2015] [Indexed: 12/20/2022] Open
Abstract
An ability to detect subtle signs of sickness in others would be highly beneficial, as it would allow for behaviors that help us avoid contagious pathogens. Recent findings suggest that both animals and humans are able to detect distinctive odor signals of individuals with activated innate immune responses. This study tested whether an innate immune response affects a person's walking speed and whether other people perceive that person as less healthy. 43 subjects watched films of persons who were experiencing experimental immune activation, and rated the walking individuals in the films with respect to health, tiredness, and sadness. Furthermore, the walking speed in the films was analyzed. After LPS injections, participants walked more slowly and were perceived as less healthy and more tired as compared to when injected with placebo. There was also a trend for the subjects to look sadder after LPS injection than after placebo. Furthermore, there were strong associations between walking speed and the appearance of health, tiredness, and sadness. These findings support the notion that walking speed is affected by an activated immune response, and that humans may be able to detect very early signs of sickness in others by merely observing their gait. This ability is likely to aid both a "behavioral immune system", by providing more opportunities for adaptive behaviors such as avoidance, and the anticipatory priming of biochemical immune responses.
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Affiliation(s)
- T Sundelin
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Department of Psychology, Stockholm University, Stockholm, Sweden
| | - B Karshikoff
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Osher Center for Integrative medicine, Karolinska Institutet, Stockholm, Sweden
| | - E Axelsson
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - C Olgart Höglund
- Osher Center for Integrative medicine, Karolinska Institutet, Stockholm, Sweden; Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden; Department of Medicine Solna and CMM, Karolinska Institutet and Karolinska University Hospital Solna, Stockholm, Sweden
| | - M Lekander
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Osher Center for Integrative medicine, Karolinska Institutet, Stockholm, Sweden; Stress Research Institute, Stockholm University, Stockholm, Sweden
| | - J Axelsson
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Osher Center for Integrative medicine, Karolinska Institutet, Stockholm, Sweden; Stress Research Institute, Stockholm University, Stockholm, Sweden.
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Sundelin T, Lekander M, Kecklund G, Van Someren EJW, Olsson A, Axelsson J. Cues of fatigue: effects of sleep deprivation on facial appearance. Sleep 2013; 36:1355-60. [PMID: 23997369 DOI: 10.5665/sleep.2964] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
STUDY OBJECTIVE To investigate the facial cues by which one recognizes that someone is sleep deprived versus not sleep deprived. DESIGN Experimental laboratory study. SETTING Karolinska Institutet, Stockholm, Sweden. PARTICIPANTS Forty observers (20 women, mean age 25 ± 5 y) rated 20 facial photographs with respect to fatigue, 10 facial cues, and sadness. The stimulus material consisted of 10 individuals (five women) photographed at 14:30 after normal sleep and after 31 h of sleep deprivation following a night with 5 h of sleep. MEASUREMENTS Ratings of fatigue, fatigue-related cues, and sadness in facial photographs. RESULTS The faces of sleep deprived individuals were perceived as having more hanging eyelids, redder eyes, more swollen eyes, darker circles under the eyes, paler skin, more wrinkles/fine lines, and more droopy corners of the mouth (effects ranging from b = +3 ± 1 to b = +15 ± 1 mm on 100-mm visual analog scales, P < 0.01). The ratings of fatigue were related to glazed eyes and to all the cues affected by sleep deprivation (P < 0.01). Ratings of rash/eczema or tense lips were not significantly affected by sleep deprivation, nor associated with judgements of fatigue. In addition, sleep-deprived individuals looked sadder than after normal sleep, and sadness was related to looking fatigued (P < 0.01). CONCLUSIONS The results show that sleep deprivation affects features relating to the eyes, mouth, and skin, and that these features function as cues of sleep loss to other people. Because these facial regions are important in the communication between humans, facial cues of sleep deprivation and fatigue may carry social consequences for the sleep deprived individual in everyday life.
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Affiliation(s)
- Tina Sundelin
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
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Mørk EK, Kristiansen K, Jørgensen HJL, Sundelin T. First Report of Golovinomyces cichoracearum as the Causal Agent of Powdery Mildew on Symphyotrichum novi-belgii (Synonym Aster novi-belgii) in Denmark. Plant Dis 2011; 95:228. [PMID: 30743433 DOI: 10.1094/pdis-10-10-0712] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Symphyotrichum novi-belgii (L.) G.L. Nesom (synonym Aster novi-belgii L.) is an autumn flowering perennial used in gardens and as a cut flower. During the last 20 years, it has been developed as a potted plant, thereby increasing its economic importance. In Denmark, 7 to 8 million S. novi-belgii plants are produced annually, making it one of the 10 most popular potted plant crops ( http://floradania.dk/index.php?id=165 ). In general, S. novi-belgii is a healthy plant, but it can be severely attacked by powdery mildew both in greenhouse production and outdoors, and diseased plants have been observed in most parts of the country. Infected plants show typical symptoms: leaf surfaces become covered with white mycelium and as the disease progresses infected leaves turn yellow and die. Powdery mildew is regarded the main disease problem in S. novi-belgii and it causes problems year round in greenhouse production. Normally, the disease is controlled by fungicides, but once out of the production system, symptom development in the retail trade will reduce the plant's appeal to customers to a degree that prevents sales. The powdery mildew identified in this study was collected in a small research field at Aarslev, Denmark in September 2004. Since collection, the pathogen has been maintained in a greenhouse on S. novi-belgii and it has been used for disease resistance screening. However, lack of proper identification of the causal agent has hindered the development of powdery mildew resistant cultivars. To identify the pathogen, the internal transcribed spacer region (ITS) of the rDNA was amplified using primers ITS1 and ITS4 (2) and sequenced. The resulting sequence was deposited in GenBank (Accession No. HM769725). BLASTn analysis of the 598-bp fragment showed 99% identity to Golovinomyces cichoracearum (DC.) V.P. Heluta from Rudbeckia laciniata L. (Accession No. AB077622). The powdery mildew colonies were slightly pink with barrel-shaped, hyaline conidia borne in chains of three to four. The length of the conidia was 30 ± 4 μm and the width was 13 ± 1 μm (n = 105). Foot cells of the conidiophores were 101 ± 16 μm long and 12 ± 5 μm wide (n = 50) with a slight constriction at the base. Chasmothecia were not observed. These morphological characteristics confirmed the identification as G. cichoracearum (1). To fulfill Koch's postulates, 10 healthy S. novi-belgii 'Victoria Fanny' plants were inoculated in an inoculation tower by shaking infected S. novi-belgii plants over the tower, resulting in a spore density of 47 spores/mm2 on the leaf surface. The infected plants were placed in a growth chamber with 16 h of light (200 μmol·m-2·s-1) and day and night temperatures of 20 and 15°C, respectively. Symptoms developed on all plants after 11 days. Colony morphology on the leaves and the morphological characteristics were as described above. Conidia were washed off the leaves, DNA extracted, and the ITS was amplified by PCR. The resulting PCR product was sequenced and was identical to HM769725. To our knowledge, this is the first report of G. cichoracearum on S. novi-belgii in Denmark. References: (1) U. Braun. The Powdery Mildews (Erysiphales) of Europe. Gustav Fischer Verlag, Jena Germany, 1995. (2) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, New York, 1990.
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Affiliation(s)
- E K Mørk
- Department of Horticulture, Faculty of Agricultural Science, Aarhus University, Kirstinebjergvej 10, DK-5792 Aarslev, Denmark
| | - K Kristiansen
- Department of Horticulture, Faculty of Agricultural Science, Aarhus University, Kirstinebjergvej 10, DK-5792 Aarslev, Denmark
| | - H J Lyngs Jørgensen
- Department of Plant Biology and Biotechnology, Faculty of Life Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark
| | - T Sundelin
- Department of Plant Biology and Biotechnology, Faculty of Life Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark
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Axelsson J, Sundelin T, Ingre M, Van Someren EJW, Olsson A, Lekander M. Beauty sleep: experimental study on the perceived health and attractiveness of sleep deprived people. BMJ 2010; 341:c6614. [PMID: 21156746 PMCID: PMC3001961 DOI: 10.1136/bmj.c6614] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
OBJECTIVE To investigate whether sleep deprived people are perceived as less healthy, less attractive, and more tired than after a normal night's sleep. DESIGN Experimental study. SETTING Sleep laboratory in Stockholm, Sweden. PARTICIPANTS 23 healthy, sleep deprived adults (age 18-31) who were photographed and 65 untrained observers (age 18-61) who rated the photographs. INTERVENTION Participants were photographed after a normal night's sleep (eight hours) and after sleep deprivation (31 hours of wakefulness after a night of reduced sleep). The photographs were presented in a randomised order and rated by untrained observers. MAIN OUTCOME MEASURE Difference in observer ratings of perceived health, attractiveness, and tiredness between sleep deprived and well rested participants using a visual analogue scale (100 mm). RESULTS Sleep deprived people were rated as less healthy (visual analogue scale scores, mean 63 (SE 2) v 68 (SE 2), P<0.001), more tired (53 (SE 3) v 44 (SE 3), P<0.001), and less attractive (38 (SE 2) v 40 (SE 2), P<0.001) than after a normal night's sleep. The decrease in rated health was associated with ratings of increased tiredness and decreased attractiveness. CONCLUSION Our findings show that sleep deprived people appear less healthy, less attractive, and more tired compared with when they are well rested. This suggests that humans are sensitive to sleep related facial cues, with potential implications for social and clinical judgments and behaviour. Studies are warranted for understanding how these effects may affect clinical decision making and can add knowledge with direct implications in a medical context.
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Affiliation(s)
- John Axelsson
- Osher Center for Integrative Medicine, Department of Clinical Neuroscience, Karolinska Institutet, 17177 Stockholm, Sweden.
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Sundelin T, Schiller M, Lübeck M, Jensen DF, Paaske K, Petersen BD. First Report of Anthracnose Fruit Rot Caused by Colletotrichum acutatum on Strawberry in Denmark. Plant Dis 2005; 89:432. [PMID: 30795468 DOI: 10.1094/pd-89-0432b] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Strawberry (Fragaria × ananassa) is the most important small fruit crop in Denmark. The quarantine pathogen Colletotrichum acutatum was detected for the first time in June 2000 in Denmark in a production field on the island of Falster. Strawberry plants of cv. Kimberly showed typical symptoms of anthracnose fruit rot. On mature fruits, brown-to-black lesions with spore masses that were orange to salmon in color were observed. Mummified berries were also observed. The fungus was isolated and identified on the basis of morphological characteristics, and identification was confirmed using enzyme-linked immunosorbent assay at the Central Science Laboratory, York, U.K. Species-specific polymerase chain reaction with the C. acutatum-specific primer pairs acut1/col2 (1) and CaInt2/ITS4 (3) also supported the identification. Additionally, the internal transcribed spacer regions, ITS1 and ITS2, of the ribosomal DNA were sequenced in both directions (GenBank Accession No. AY818361). Homology searches with this sequence using BLAST also confirmed the identity. Colonies grown on potato dextrose agar developed white-to-grey aerial mycelium with salmon-colored spore masses, and were beige to black on the reverse side. Conidia were 11.3 (7.3 to 16.6) μm × 3.9 (2.5 to 5.2) μm, hyaline, cylindrical with at least one pointed end, and aseptate. Mycelial growth rate was 8.4 mm per day at 25°C which is similar to earlier reports (2). Spray-inoculated (106 conidia per ml) strawberry fruits cv. Elsanta developed brown, sunken, irregular lesions with salmon-colored acervuli after 2 to 5 days at 25°C. Koch's postulates were fulfilled since the reisolated fungus from these lesions developed the same morphological characteristics as described above. To our knowledge, this is the first report of C. acutatum in Denmark. References: (1) P. V. Martinez-Culebras et al. J. Phytopathol. 151:135, 2003. (2) B. J. Smith et al. Plant Dis. 74:69, 1990. (3) S. Sreenivasaprasad et al. Plant Pathol. 45:650, 1996.
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Affiliation(s)
- T Sundelin
- Department of Plant Biology, The Royal Veterinary and Agricultural University, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
| | - M Schiller
- Department of Plant Biology, The Royal Veterinary and Agricultural University, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
| | - M Lübeck
- Department of Plant Biology, The Royal Veterinary and Agricultural University, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
| | - D F Jensen
- Department of Plant Biology, The Royal Veterinary and Agricultural University, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
| | - K Paaske
- Danish Institute of Agricultural Sciences, Research Centre Flakkebjerg, 4200 Slagelse, Denmark
| | - B D Petersen
- Fruit and Vegetable Advisory Service, Industrivej 31C, 4230 Skaelskør, Denmark
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